Re: What health hazards of 50% solution of nitric acid/water to etch pewter

The Best way for you to assess the dangers associated with any chemical are 
to read and understand the Material Safety Data Sheet (MSDS). Manufacturers 
and distributers of all chemicals are required to supply these with every 
shipment and upon request. 

I have included an excerpt from the MSDS for Nitric Acid which I obtained 
from http://hazard.com. You can use this site to link to several databases 
of MSDSs. The excerpt for the Nitric Acid health hazard is below.






                  CHEMICAL DANGERS:
                  The substance decomposes on warming producing
                  nitrogen oxides. The substance is a strong oxidant and
                  reacts violently with combustible and reducing materials,
                  e.g., turpentine, charcoal, alcohol. The substance is a
                  strong acid, it reacts violently with bases and is
                  corrosive to metals. Reacts very violently with organic
                  chemicals (e.g., acetone, acetic acid, acetic anhydride),
                  causing fire and explosion hazard. Attacks some plastics.




You should view the entire MSDS available at:

 http://www.vetmed.ucdavis.edu/msds/mf/cards/files/0183.html